This invention relates generally to door latch strikers and more particularly to a vehicle door latch striker, which may be at least partially covered with plastic, having a threaded striker bolt.
The sound made by a vehicle""s door when closing is a characteristic often identified by consumers with the quality of the vehicle""s construction. It is particularly appealing to potential new vehicle purchasers, and, not surprisingly, particularly important to vehicle manufacturers, that the vehicle doors make a solid and secure sound when they are shut. This sound is dependent, in large part, on the nature and quality of the door latch and striker designs and the interaction between the two parts. A hollow or tinny sound full of vibrations and reverberations is undesirable and a solid, vibration-free sound is preferred.
Various safety requirements, including those set by governmental agencies and vehicle manufacturers, dictate that striker bolts and door latching systems resist opening in the event of a crash or other mishap so as to protect the occupants of the vehicle from injury. In fact, out of an extraordinary concern for safety, vehicle manufacturers typically set safety requirements more stringent than those which are governmentally imposed.
Automobiles and other vehicles are generally equipped with a latch in the end of each door that engages a striker secured to the vehicle body pillar at the edge of the door opening. The latch in the door typically includes a slot that opens toward the vehicle interior and extends through a cutout in the face plate of the door. This slot guides the latch over the striker as the vehicle door is closed. As the latch moves over the striker, a pivotally mounted fork bolt that is part of the latching mechanism xe2x80x9cstrikesxe2x80x9d and engages the striker. The striker causes the fork bolt to rotate to a latched position wherein the fork bolt engages the striker to hold the door closed. The fork bolt is held in the latched position until it is released by actuation of a door handle or other mechanism.
Examples of existing door latch mechanisms are disclosed, for example, in U.S. Pat. No. 4,130,308 to Jeavons; U.S. Pat. No. 5,000,495 to Wolfgang et al.; U.S. Pat. No. 5,520,426 to Arabia Jr. et al.; U.S. Pat. No. 5,348,357 to Konchan et al.; and U.S. Pat. No. 5,632,517 to Paulik et al. These door latches secure the vehicle door to the door frame by engagement with a door latch striker attached to the vehicle frame. Existing door latch strikers generally have a bolt or projection that is riveted to a base or bracket that secures the striker to the door pillar. Examples of such designs are disclosed in a number of U.S. Patents including U.S. Pat. No. 4,941,696 to Yamada et al.; U.S. Pat. No. 4,998,759 to Peterson et al.; U.S. Pat. No. 5,050,917 to Hamada et al.; U.S. Pat. No. 5,209,531 to Thau; and U.S. Pat. No. 5,707,092 to Van Slembrouck et al. Each of these designs and many other conventional designs suffer from several limitations and drawbacks, most notably, a weak rivet connection which cannot effectively meet the vehicle manufacturers"" more stringent safety standards for securing vehicle doors in the closed position. The use of a rivet connection limits the ability to use high strength or heat treated materials for the striker bolt and the base or mounting plate. Thus, a major cause of failure of the door latching mechanism in vehicles is the failure of the striker bolt itself or failure of the rivet connection between the striker bolt and the mounting plate. Also, these striker bolt designs do not result in the preferred solid, reverberation-free closing sound that is sought by vehicle consumers and manufacturers.
Conventionally, strikers have almost exclusively been made entirely of metal. This results in an unpleasant sounding metallic impact and friction when engaging with door latches, and may cause uneven contact with a latch or a guide piece and/or may cause play in the engagement between the striker and the door latch after excessive wear. These occurrences impair durability as a result of wear and breakage and may cause annoying or unappealing noises. There have been several attempts made to solve the problems existing in conventional strikers, some of which include the use of plastic or other polymeric or elastomeric material. However, as explained in further detail below, each of these attempts has some drawbacks and does not fully satisfy the needs of vehicle manufacturers.
U.S. Pat. No. 4,466,645 to Kobayashi and U.S. Pat. No. 4,981,313 to Makamura disclose the use of a plastic material overmolded over a conventional U-shaped, riveted striker assembly. The objective of providing the plastic overmolding is better noise reduction when the door latch engages the striker. However, such designs are subject to excessive wear at the point where the latch mechanism engages the striker. After repeated engagements, the plastic coating may be so fully worn at the impact point that the metal latching mechanism impacts the metal bolt causing the problems outlined above.
U.S. Pat. No. 5,215,342 to Yuge et al. discloses generally a striker with a plastic cover. The striker includes a base plate; a plastic overmolded, generally U-shaped rod riveted to the base plate; and a molded plastic cover sized to cover a major surface of the base plate to provide an attractive appearance. The cover has an elongate slit which is constructed to permit the U-shaped rod to pass therethrough and the cover includes two circular openings sized as to make a latched engagement when the plastic cover is properly attached to the base plate. This striker assembly also suffers from the deficiencies described above with respect to the assemblies disclosed in U.S. Pat. Nos. 4,466,645 and 4,981,313. Additionally, the engagement of the plastic cover requires an additional step in the automobile assembly process.
A more recent striker design, shown in FIG. 1 and identified generally as A, includes a plate B and a bolt C. The plate B is stamped into a generally U-shaped piece having striker bolt holes D and E and mounting bolt holes F therethrough. The striker bolt C slides through striker bolt hole D and is riveted in place through striker bolt hole E to close the U-shape of the plate B. The striker A is affixed to the door frame through the mounting bolt holes F. This design suffers from several of the limitations described above, e.g., the riveting of the striker bolt cannot meet strength objectives and the metal on metal impact and friction causes an undesirable closing sound and may lead to play in the engagement between the striker and door latch after excessive wear. The use of a smooth-bore extruded plastic sleeve around the bolt C is similar to the overmolded designs discussed above. Such a sleeve does not absorb a significant amount of impact energy and, if the sleeve is tightly fitted around the bolt so that it is not free to rotate, the sleeve is prone to wear after repeated strikings by the latch in the same place.
Accordingly, a need exists for a vehicle door striker that is capable of meeting or exceeding manufacturer safety requirements for door latches, has an attractive appearance, is cost effective to manufacture and install on the automobile, and makes the solid, reverberation-free closing sound that is appealing to vehicle consumers and manufacturers.
Therefore, it is an object of the present invention to provide a vehicle door striker that is capable of exceeding governmental and the more stringent vehicle manufacturer safety requirements. It is a further object of the invention to provide a vehicle door striker that has an attractive appearance. It is an additional object of the invention to provide a vehicle door striker that is durable and cost effective to manufacture and to install on the automobile. It is yet another object of the invention to provide a vehicle door striker that makes a sound when the door is closed that is appealing to consumers. It is still a further object of the present invention to provide a vehicle door striker that overcomes the disadvantages of the prior art. The vehicle door striker of the present invention provides the above identified and many additional objects by providing a striker that includes very few parts, is easily assembled and installed, is of very high strength, provides the solid, reverberation-free closing sound that is appealing to consumers and manufacturers, and is cost effective.
As described in more detail below and shown in the accompanying drawings, the vehicle door striker of the present invention includes a generally U-shaped striker plate formed from stamped steel. One arm of the U includes a mounting plate with mounting bolt holes and a striker bolt hole therethrough. The other arm of the U is a support arm that has a threaded boss with a hole therethrough substantially in axial alignment with the striker bolt hole in the mounting plate. A striker bolt is inserted through the striker bolt hole in the mounting plate and is threaded into the threads of the boss until the larger diameter bolt shaft is proximal to the boss. The use of a threaded connection in the boss provides a much stronger connection and, if desired, allows the use of much higher strength steel for the bolt and the plate than is used with conventional riveted striker bolts. The threaded connection and the larger bolt shaft diameter as compared to the threaded boss hole also help retain the support arm in position and help prevent it from collapsing if impacted. In one embodiment of the invention, a threaded connection in accordance with the present invention is incorporated into existing striker designs and configurations to achieve a higher strength connection.
The striker bolt may be fitted with a sleeve made from extruded or injection molded plastic, polyurethane, nylon, or other suitable material. The sleeve can be slid over the bolt before or as it is threaded into the boss, however, assembly is facilitated by sliding the sleeve over the bolt before inserting the bolt through the striker bolt hole. In one embodiment, the striker bolt has a smooth exterior surface with a profiled plastic sleeve fitted over the exterior diameter of the bolt so as to leave at least some space between the parts. The sleeve is preferably substantially free to rotate around the bolt when impacted by the door latch. The use of the profiled plastic sleeve provides both better noise reduction and better wear resistance than can be achieved with a smooth-bore sleeve. In alternative embodiments, the interior surface and/or the exterior surface of the sleeve may have a variety of shapes which are designed to affect the noise produced when the door is closed or to resist wear. Instead of a smooth shape, the surface of the striker bolt is configured in a series of annular rings along its length or may be splined. Such shapes also affect noise and wear resistance. In another alternate embodiment, the sleeve is overmolded over the striker bolt and is not free to rotate.
In an additional embodiment, the striker assembly is covered with a plastic cover so as to provide an attractive appearance, further reduce noise, and further resist wear and corrosion. In this embodiment, a one-piece cover slides over the U-shaped striker plate. The striker bolt is then threaded into the boss to lock the cover over the plate and complete the striker assembly. The plastic cover may include an integrated sleeve or one of the previously described extruded, injection molded, or overmolded sleeves may be used. If an integrated sleeve is used, there is preferably a gap between the bolt and the sleeve so as to isolate and dampen sound. When the cover is used, the striker assembly is fully insulated from the car body to help dampen noise and prevent vibration.
As previously noted, the mounting plate of the U-shaped striker plate has striker bolt holes therethrough. The striker can be affixed to the vehicle door frame through the mounting bolt holes. In the plastic cover embodiment, the mounting bolts may be partially inserted through the mounting bolt holes and held in place by interference with the plastic cover. Such an arrangement provides the installer with a complete door latch striker package which facilitates assembly line installation of the striker plate on the door frame.
In sum, the present invention represents a significant improvement over the prior art in many ways. Vehicle door strikers in accordance with the present invention are capable of exceeding governmental and the more stringent vehicle manufacturer safety requirements, are durable and cost effective, and make a solid, reverberation-free closing sound that is appealing to vehicle consumers and manufacturers. These and other objects and advantages of the present invention will become apparent from the detailed description and accompanying drawings.